Example of Mandarin characters that can not be expressed through other characters, Kangxi radicals or CJK strokes?

Question

I had question about the expression of one character into the radicals and I found the answer myself Does 习 contain the alterantive hook (Kangxi 6) radical and is more information available about this alternative form? that there are CJK strokes besides radical.

So - my question is - do Kangxi radicals + CJK strokes form the complete basis of Mandarin (Simplified Chinese) characters, i.e. whether every Mandarin character can be expressed as combination of other characters, Kangxi radicals and CJK strokes?

If not, then could someone provide some example characters which can not be decomposed into such parts and some reason why is that?

Added - question explained: my aim is to find the complete basis of the radicals and strokes from which every character can be built and use this basis for the memorization of characters (I am also building application that shows such associations; associations, system, compositionality and structure help memorization). If Kangxi radicals + CJK strokes will not form the complete basis (i. e. if there are evidence of characters that require additional strokes) then I will try to find the systemic extension of the sets of strokes that are necessary to finally come up with the complete basis or radicals and strokes. But for that I will make new question. This question is just about the possibility of counterxamples to Kangxi+CJK hypothesis. If the answers will point to some possible systematic extension of this basis - then ever better.

Answer 1

Not totally sure if I understand what you're getting at, but this character should fit your criteria:

This is a character from BabelStone Han PUA.

As you can see its Ideographic Description Sequence is just marked:

?

The basis for its digitization originates from《隸定古文疏證》(2002) page 261:

UK IRG does try to split it into:

IDS=⿱⿰丨㇎一

and

丨 (U+4E28)
㇎ (U+31CE)
一 (U+4E00)